Tree of nodes

I have a table recording a tree of nodes. under each node there could be 0, 1 or more records representing documents. How can I recreate the tree of node with the number of documents attached to a node or its sub nodes ?

ex :
-- node-1

  document 1
  document 2
-- node-1.1

  document 3
-- node-2

• node-2.1 document 4 document 5 document 6
• node-2.2 document 7
• node-3 ...

the SQLRequest would present this tree of node like this :

node-1  has 3 documents
node-1.1 has 1 document
node-2  has 4 documents
node-2.1 has 3 documents
node-2.2 has 1 document
node-3  has 0 document

The table structure is as follow
create table toto ( obj_idy number, obj_peridy number, obj_type number, obj_name varchar(100));

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Véronique Alcindor Davis
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